GE Multilin
G60 Generator Protection System
B-3
APPENDIX B
B.1 MODBUS RTU PROTOCOL
B
Table B–3: MODBUS RTU CRC-16 ALGORITHM
SYMBOLS:
-->
data transfer
A
16 bit working register
Alow
low order byte of A
Ahigh
high order byte of A
CRC
16 bit CRC-16 result
i,j
loop counters
(+)
logical EXCLUSIVE-OR operator
N
total number of data bytes
Di
i-th data byte (i = 0 to N-1)
G
16 bit characteristic polynomial = 1010000000000001 (binary) with MSbit dropped and bit order reversed
shr (x)
right shift operator (th LSbit of x is shifted into a carry flag, a '0' is shifted into the MSbit of x, all other bits
are shifted right one location)
ALGORITHM:
1.
FFFF (hex) --> A
2.
0 --> i
3.
0 --> j
4.
Di (+) Alow --> Alow
5.
j + 1 --> j
6.
shr (A)
7.
Is there a carry?
No: go to 8; Yes: G (+) A --> A and continue.
8.
Is j = 8?
No: go to 5; Yes: continue
9.
i + 1 --> i
10.
Is i = N?
No: go to 3; Yes: continue
11.
A --> CRC
Содержание Multilin g60
Страница 10: ...x G60 Generator Protection System GE Multilin TABLE OF CONTENTS INDEX ...
Страница 32: ...1 22 G60 Generator Protection System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Страница 130: ...3 68 G60 Generator Protection System GE Multilin 3 4 FIELD AND STATOR GROUND MODULES 3 HARDWARE 3 ...
Страница 160: ...4 30 G60 Generator Protection System GE Multilin 4 3 FACEPLATE INTERFACE 4 HUMAN INTERFACES 4 ...
Страница 486: ...5 326 G60 Generator Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Страница 518: ...6 32 G60 Generator Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Страница 532: ...7 14 G60 Generator Protection System GE Multilin 7 2 TARGETS 7 COMMANDS AND TARGETS 7 ...
Страница 538: ...8 6 G60 Generator Protection System GE Multilin 8 1 PHASE DISTANCE THROUGH POWER TRANSFORMERS 8 THEORY OF OPERATION 8 ...
Страница 748: ...D 10 G60 Generator Protection System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
Страница 760: ...E 12 G60 Generator Protection System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...